Umbrella



FIG. 1 is a front elevational view of an umbrella showing my new design;

FIG. 2 is a partial right-side elevational view thereof;

FIG. 3 is a partial left-side elevational view thereof;

FIG. 4 is a partial rear elevational view thereof;

FIG. 5 is a bottom plan view thereof; and

FIG. 6 is a top plan view thereof. 

The ornamental design for an umbrella, as shown and described. 